ATTLEBORO - The approval of an urban renewal plan by the city council Tuesday paves the way for big changes downtown, but it doesn't mean the bulldozers are warming up.

It will be months, most likely August, before there's any visible activity, said Attleboro Redevelopment Authority Executive Director Michael Milanoski.

State approvals and financing must be in place before destruction and construction work can begin in the 32-acre Riverfront District, where the first phases of the long-term project will take place, he said.

Plans call for transportation improvements and the construction of condominiums and commercial areas in the parcel bounded roughly by Olive Street, the Amtrak railroad, County Street and Ten Mile River.

But most of the first phase involves land acquisition and clearing so that it can be sold to developers. Before that happens, the urban renewal plan needs to be approved by the state's Department of Housing and Community Development. It also has to pass muster at MEPA, the Massachusetts Environmental Policy Act office, which conducts environmental reviews of projects that are required to get state approval.

Milanoski is not anticipating problems with either, but the reviews will take time, he said.

While officials at DHCD have been kept apprised of ARA plans, the department's scrutiny is anticipated to take 60 days.

"I expect them to do their due diligence," Milanoski said. "But hopefully by the end of May, we'll have state approval to move the project forward."

Once the state signs off on the plan, City Treasurer Ethel Sandbach will be able to seek a $2,539,000 loan that represents the city's share of the $14.7 million cost for the first phase of the project, Milanoski said.

The city council authorized the loan Tuesday with a 10-1 vote.

But the borrowing process is likely to take some time as well, Milanoski said.

He expects the money to be available to the ARA by the end of July.

"At that point, we hope to close on several of the properties and begin to implement the project," Milanoski said. "By August, we should be in implementation mode."

The first steps of the project will include the acquisition of property and the relocation of the businesses which occupy it. Relocation of the city's public works yard will be pursued simultaneously and preliminary environmental assessments will be ongoing, he said. The businesses to be relocated are Automatic Machine Co. on Wall Street and Attleboro's Old Barn on South Main Street.

The ARA has purchase-and-sales agreements with both.

One of the first construction jobs may be the installation of a new access to the MBTA commuter rail parking lot from Wall.

The ARA would demolish a building it owns at 8 Wall St. to put in the access.

The access will be designed to alleviate dangerous conditions and congestion that currently exist at the South Main Street access.

GEORGE W. RHODES can be reached at 508-236-0432 or at grhodes@thesunchronicle.com.